This invention relates to the production of cyano acetals. More particularly it relates to a method of improving the selectivity of formation of cyano acetals by the catalytic reaction of a nitrile, an alcohol, CO and H.sub.2.
It is known to synthesize acetals containing a cyano group by hydroformylation. For example in U.S. Pat. No. 3,466,317 a process is disclosed wherein acetonitrile or alkyl-substituted derivatives thereof are reacted with a lower alkanol, CO and H.sub.2 in the presence of a Group VIII metal-containing, hydrogenating catalyst and an acid at pressures of at least 60 atmospheres. The presence of the acid advantageously permitted the use of lower operating pressures.
Known methods of synthesis however continue to be unsatisfactory because of a tendency of the generally used CO.sub.2 (CO).sub.8 catalyst to become unstable at elevated temperatures thereby promoting the formation of undesirable by-products.